ST. PETERSBURG, Fla.— The Center for Biological Diversity filed a formal notice today of its intent to sue the U.S. Fish and Wildlife Service over the agency’s failure to designate critical habitat for the Suwannee moccasinshell, found in north Florida.

The moccasinshell was feared extinct but rediscovered in the Suwannee, Upper Santa Fe and Withlacoochee rivers. The Center filed a scientific petition to list the 2-inch mollusk under the Endangered Species Act in 2010 and followed up with several lawsuits to force decisions leading to the moccasinshell’s protection.

The Service proposed designating more than 100 miles of rivers as critical habitat over a year ago, but has now missed the deadline to finalize the designation.

“Florida’s freshwater mussels are quirky and cool, but they are also harmed by our land and water-use decisions,” said Jaclyn Lopez, Florida director of the Center. “Critical habitat will help protect the rivers the Suwannee moccasinshell calls home.”

With only 25 species protected as threatened or endangered, delay and denial of habitat protections and significant regulatory rollbacks, the Trump administration has the worst record protecting species of any administration since Congress passed the Endangered Species Act.

The Act prohibits federal agencies from authorizing activities that will destroy or harm a listed species’ critical habitat. Species with federally protected critical habitat are more than twice as likely to be recovering as those without it.

Earlier this year the Center filed suit in Washington, D.C. over more than 200 species awaiting decisions about their protection. In addition to the Suwannee moccasinshell in today’s notice, the Center plans to initiate lawsuits for another 20 species waiting for listing and 88 species waiting for designation of critical habitat. Further, the Center hopes to work out a schedule with the Biden administration to ensure these species from across the country get protection and avoid extinction.

The Suwannee moccasinshell attracts darter fish with a flashy, blue wiggling lure, then shoots its fertilized eggs into the fishes’ gills. The fish swim away, and the mussel’s offspring eventually drop off onto the river bottom. An increase in agricultural irrigation has lowered the Upper Floridan aquifer near the Suwannee River Basin, severely threatening the mussel by depleting and polluting the waters in the rivers that sustain it. A proposed phosphate mine also threatens river habitat in Bradford and Union counties.